Abstract
In measuring the adhesiveness of sprayed metal coatings to steel we improved the ASTM jig used for measuring the adhesiveness of rubber sheets to metals. We could obtain so far the reasonable data by means of measuring tensile strength of sprayed coatings adhered to the jig with Araldite.
On zinc coatings, for instance, the sprayed coating by powder spraying method showed far superior adhesiveness to the ones sprayed by arc and flame spraying methods.
It was found that steel grit blasting was the best pre-treatment method, and sand blasting and emery blasting werg inferior to the former. But if the grit blasting was incomplete, the coating showed rather lower adhesiveness.
Aluminum, brass, copper, etc. showed comparatively good adhesiveness, from the viewpoint of which they were superior to soft metals such as lead and tin.
Molybdenum coatings, when used for an undercoat of ferrous sprayed coatings, took an excellent effect as a bonding coat. Being able to increase the adhesiveness of ferrous coatings at least 1.5 to 2.0 time as much, this treatment is the most suitable for pre-treating a repair part required firm adhesiveness.
